With rapid popularization of a Long-Term Evolution (LTE) technology, mobile internet provides a multimedia application with high definition and high performance. As a result, a mobile data service grows rapidly, and power consumption of a mobile terminal device increases significantly, which poses an unprecedented challenge to heat dissipation design within limited space.
A high-temperature surface region for heat dissipation during working of a mobile terminal device is corresponding to a position of a main central processing unit (CPU) on an L-shaped printed circuit board (PCB). Because power consumption is concentrated in a CPU and a graphics processing unit (GPU), temperature distribution in thermal design is seriously uneven. Heat conduction performance of a die casting magnesium alloy (a coefficient of thermal conductivity k: k≤70 watts per meter Kelvin (W/m-K)) and a graphite film (a thickness t: t=0.02−0.1 millimeters (mm); a coefficient of thermal conductivity k: k=−1200 W/m-K) that originally connect a cold region and a hot region cannot meet a higher thermal design requirement of a user. Therefore, how to effectively dissipate heat of a mobile terminal is an urgent problem that needs to be resolved in the industry.